2,3,3,3-Tetrafluoropropene (CF3CF═CH2, HFO-1234yf) contains no chlorine and thus is useful as an alternative compound for chlorofluorocarbons to be used for e.g. refrigerants.
As a process for producing HFO-1234yf, a process may, for example, be mentioned wherein 1,1-dichloro-2,2,3,3,3-pentafluoropropane (CF3CF2CHCl2, HCFC-225ca) is subjected to a dehydrofluorination reaction to obtain 1,1-dichloro-2,3,3,3-tetrafluoropropene (CF3CF═CCl2, CFO-1214ya), and then, CFO-1214ya is reacted with hydrogen and reduced to obtain HFO-1234yf.
As a method of reducing CFO-1214ya to obtain HFO-1234yf, the following method (i) may, for example, be mentioned.
(i) A method for obtaining HFO-1234yf by reacting CFO-1214ya and hydrogen in the presence of a catalyst having palladium supported on alumina (Patent Document 1).
However, the catalyst used in the method (i) has a drawback such that while the durability is high, side reactions are substantial to form by-products which can hardly be separated by distillation, and the conversion ratio to HFO-1234yf is low.
On the other hand, as a method for carrying out a similar reduction reaction, the following method (ii) has been proposed.
(ii) a method of reacting RfCF═CX2 (wherein Rf is a C1-10 fluoroalkyl group, and X is chlorine, bromine or iodine) with hydrogen in the presence of a catalyst having palladium supported on active carbon, to obtain RfCF═CH2 (Patent Document 2).
However, the catalyst used in the method (ii) has low durability in many cases, whereby it is required to change the catalyst frequently.
Prior Art Documents
Patent Documents
Patent Document 1: WO2008/060614
Patent Document 2: JP-A-2-286635